| Title |
Pseudoelasticity and Cyclic Deformation effect in Ni - Ti alloy |
| Authors |
지광구(K . K . Jee); 신명철(M . C . Shin) |
| Abstract |
Pseudoelasticity and cyclic deformation effect in Ni-Ti alloy were studied. A method of predicting σ_M and σ_R - stress for martensitic and reverse transformation above Af temperature, respectively - by the ΔH and the temperature of transformation was newly proposed using Clausius-Clapeyron equation. By cyclic deformation above Af temperature, the σ_M and σ_R decreased due to anisotropic stress field of the dislocations generated during the deformation. With Δσ_M-the quantity of decreased in σ_M-three to four times larger than Δσ_R, Δσ_M increased with test temperature. But Δσ_M did not change with varying the amount of deformation strain. Heat treatment at 300℃ for 30sec after cyclic deformation could recover its original σ_M and σ_R by eliminating the stress field of the dislocations. |